package utils;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.util.Random;

public class VerifyCodeUtil {

    /**
     * 动态生成图片
     */
        // {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"}
        private static String[] fontNames = { "宋体", "华文楷体", "黑体", "微软雅黑",  "楷体_GB2312" };
        // 1可选字符abcdefghjkmnopqrstuvwxyz123456789ABCDEFGHJKMNPQRSTUVWXYZ
        // 2可选字符1234567890
        private static String codes = "ababcdefghijklmnopqrstuvwxwz";
        // 背景色
        private static Color bgColor = new Color(255, 255, 255);
        // 基数(一个文字所占的空间大小)
        private static int base = 30;
        // 图像宽度
        private static int width = base * 4;
        // 图像高度
        private static int height = base;
        // 文字个数(可调)
        private static int len = 4;
        // 设置字体大小
        private static int fontSize = 22;
        // 验证码上的文本
        private static String text;

        private static BufferedImage img = null;
        private static Graphics2D g2 = null;

        /**
         * 生成验证码图片
         */
        public static void drawImage(OutputStream outputStream) {
            // 1.创建图片缓冲区对象, 并设置宽高和图像类型
            img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            // 2.得到绘制环境
            g2 = (Graphics2D) img.getGraphics();
            // 3.开始画图
            // 设置背景色
            g2.setColor(bgColor);
            g2.fillRect(0, 0, width, height);

            StringBuffer sb = new StringBuffer();// 用来装载验证码上的文本

            for (int i = 0; i < len; i++) {
                // 设置画笔颜色 -- 随机
                // g2.setColor(new Color(255, 0, 0));
                g2.setColor(new Color(getRandom(0, 150), getRandom(0, 150),getRandom(0, 150)));

                // 设置字体
                g2.setFont(new Font(fontNames[getRandom(0, fontNames.length)], Font.BOLD, fontSize));

                // 旋转文字(-45~+45)
                int theta = getRandom(-45, 45);
                g2.rotate(theta * Math.PI / 180, 7 + i * base, height - 8);

                // 写字
                String code = codes.charAt(getRandom(0, codes.length())) + "";
                g2.drawString(code, 7 + i * base, height - 8);
                sb.append(code);
                g2.rotate(-theta * Math.PI / 180, 7 + i * base, height - 8);
            }

            text = sb.toString();

            // 画干扰线
            for (int i = 0; i < len + 2; i++) {
                // 设置画笔颜色 -- 随机
                // g2.setColor(new Color(255, 0, 0));
                g2.setColor(new Color(getRandom(0, 150), getRandom(0, 150),
                        getRandom(0, 150)));
                g2.drawLine(getRandom(0, 120), getRandom(0, 30), getRandom(0, 120),
                        getRandom(0, 30));
            }
            // 4.保存图片到指定的输出流
            try {
                ImageIO.write(img, "JPEG", outputStream);
            } catch (Exception e) {
                e.printStackTrace();
                throw new RuntimeException(e);
            }finally{
                // 5.释放资源
                g2.dispose();
            }
        }

        /**
         * 获取验证码字符串
         * @return
         */
        public static String getCode() {
            return text;
        }

        /*
         * 生成随机数的方法
         */
        private static int getRandom(int start, int end) {
            Random random = new Random();
            return random.nextInt(end - start) + start;
        }

        public static void main(String[] args) throws Exception {
            VerifyCodeUtil tc = new VerifyCodeUtil();
            tc.drawImage(new FileOutputStream("d:/图片验证码.jpg"));
            System.out.println("图片验证码为---->"+tc.getCode());
            System.out.println("执行成功~!");
        }

    }
